The invention is directed to the subject matter recited in the patent claims. In particular, the invention is directed to a method for manufacturing pressed, shaped and at least partially porously fashioned detergent, cleaning agent, disinfectant and/or preservative without employing a pre-heated melt or solution, whereby a pre-fabricated premix composed of powdered and/or granulated active ingredients manufactured with or without mixing this prefabricated mixture with a binder is filled into a suitably shaped, shape-stable, stackable and refillable returnable container without undercuts and is compressed under pressure, so that a compact block having powder structure consolidated in the container is formed.
The invention is also directed to recyclable, upwardly open as well as conically upwardly expanding returnable containers that can be utilized for liquid, solid or, respectively, powdered detergent, cleaning agent, disinfectant and/or preservative and that, in particular, can be utilized in dishwashers and washing machines for the implementation of the afore-mentioned method. In particular, the invention is directed to reemployable or, respectively, recyclable returnable containers particularly suitable for employment in washing machines that contain detergent, cleaning agent, disinfectant and/or preservative, said returnable containers being fashioned such that detergent, cleaning agent, disinfectant and/or preservative is delivered from the container when a stream of aqueous liquid is placed on a surface of the detergent, cleaning agent, disinfectant and/or preservative exposed to said stream of aqueous liquid. The invention, finally, is directed to the employment of this returnable container. It is critical for the container of the invention including the cover thereof that both the filled and closed container as well as the empty container and the cover is (are) fashioned stackable in and of itself (themselves).
Advantageous embodiments of the invention are contained in the subclaims.
In addition to liquid, paste-like or powdered detergents, shaped, piece-shaped, solid detergent products have been known and in use for a long time such as, for example, bars of soap, syndet bars of soap, toilet cones or tablets, shaped detergents for dishwashers and washing machines, etc.
A general overview is contained, for example, in the publication by H. E. Tschakert, "Seifen", Oele, Wachse, 98 (1972) 793-801, 845-849 and Ibid. 99 (1973) 3-7.
In addition to the manufacture of such shaped, piece-shaped detergent products by pressing and extruding processes (to form tablets, briquettes and the like), manufacture by pouring a solution or melt capable of solidification into forms has been standard for a long time, this having the advantage compared to pressing that complicated and, for example, irregularly structured shaped pieces can also be manufactured in a simple way.
The solution or melt is frequently poured into the molds in the heated condition in this case and they solidify when cooled.
The shaped pieces can either be removed from the molds after the solidification and can reach the user in a separate packing or, on the other hand, the container employed as mold simultaneously serves as packaging for the shaped detergent piece and reaches the user connected thereto, whereby the amount of detergent required for the respective use in every employment is generally released from the shaped, piece-shaped detergent product in its envelope due to the action of corresponding solvents, usually water.
Examples of such product formulations and manufacturing methods are recited, for example, in Tenside 8 (1991) 275, in Tenside 11 (1974) 330, in Seife, Oele, Fette, Wachse 96, No. 23 (1970) 823 as well as, in particular, in the afore-mentioned publication by H. E. Tschakert.
Likewise, the "Jahrbuch fuer den Praktiker", Verlag fuer Chem. Ind. Ziolkowski, Augsburg, 1972, p. 194, 1973, p. 229, 1974, p. 110 and pp. 132, 134, 135, 1975, pp. 116, 117, 118, 1976, pp. 116-120, which is well-known to a person skilled in the art active in this field provides various exemplary formulations for shaped detergent pieces that are manufactured by pouring a heated melt or, respectively, solution into molds and by solidification during cooling.
Recently, patent literature has also concerned itself with the method for manufacturing shaped, solid cleaning agents by filling a heated melt or, respectively, solution into molds and solidification during cooling; thus, for example, European patent application 0 003 769, European patent application 0 307 587, pouring alkaline aqueous solution, as well as German patent applications DE 35 19 353, DE 35 19 354, DE 35 19 355, DE 36 34 812.
All of these published manufacturing methods for solid, shaped detergent members are affected by production-related or qualitative disadvantages, since
a) only specific, simple molds can be produced in the case of manufacture by pelleting, briquetting, etc., and extremely complicated systems are also required for processing; PA1 b) considerable energy is required for melting the initial mixtures and keeping them warm in the case of manufacture on the basis of pouring a melt or heated solution into a mold and thermally sensitive constituents of the formula suffer increased damage or, respectively, a higher degree of degradation or, respectively, decomposition as a consequence of the dwell at a higher temperature that necessary lasts a longer time than if no heating or only an extremely brief-duration heating were to occur. PA1 1. Complete, optimally simple residual emptying before being returned for refilling (because of unproblematical transport and contamination-free refilling). PA1 2. Designing the product containers in such a way that, in their emptied condition, these become reducible in terms of volume by a reduction factor of approximately five (transport costs are calculated based on volume). PA1 3. User safety in view of the dosing systems, i.e. the automatic dosing system is to be designed such in combination with the product containers that the users are protected from contact with the product. PA1 4. Stable, long-lasting implementation for an optimally long service life, i.e. a higher number of refillings. Labeling impressed insofar as possible, milled or applied non-erasably in some other way so that reliable sorting according to type of product can be implemented before refilling-without additional labeling. PA1 5. Container and closure material identical with good, environmental disposal possibility in the ultimate disposal.
EP-A-0242966 shows the solidification of a granular detergent mixture in a container by pouring an aqueous solution in that is heated to more than 66.degree. C. through 83.5.degree. C., this then filling the interspace from top to bottom without agitation.
This procedure has the disadvantage that an excessively rapid solidification of the upper part in the mixture in the container easily ensues upon initial contact of the impregnating liquid with the podwer mixture, so that the liquid does not or does not adequately impregnate the lower parts of the mixture, particularly when fine constituents are present due to abrasion, and an incomplete formation of a block occurs in this way.
EP-A-0 375 022 discloses a detergent pellet that has been pressed under extremely high pressure (3-30 KN/cm.sup.2). Such detergent can then be employed for commercial dish washing.
U.S. Pat. No. 4,808,236 discloses the manufacture of a piece-shaped detergent product by pouring a solution capable of solidification or a melt into a form. This solution or melt then solidifies upon cooling and remains in the container employed as mold.
WO 89/11753 is directed to shaped detergent pieces that contain pre-shaped chlorine cores or sources. These shaped pieces are manufactured by pouring a solution capable of solidification into a mold. The shaped pieces are in turn removed from the mold after solidification and can be utilized in dishwasher machines at low water temperatures.
The Derwent abstract of JP-A-1161100 discloses a detergent mixture packed in a container that has a high bulk density (0.5-1.2 g/cm.sup.2).
EP-A-0 225 859 discloses a dosing apparatus for dissolving detergents. A block detergent product is introduced into a housing, this product then being sprayed from below with a nozzle, so that the detergent can proceed via a conduit into the rinsing water. The containers for the block or briquette product are cylindrically fashioned and have a foil covering at their upper end.
As stated above, specific containers are utilized as mold or as packaging of the detergent, cleaning agent, disinfectant and/or preservative. In Germany and Europe, however, there is a requirement to the effect of designing or, respectively, utilizing reemployable containers whose raw material, moreover, is also recyclable.
Due to increasing quantities of garbage, there is an increased need for packaging systems that manage with optimally small packaging volumes relative to the filling quantity. Over and above this, the requirement is directed to mono packaging materials that can be simply are reliably completely emptied, particularly when filled with hazardous substances. One possibility for chemical products such as, for example, cleaning agents is comprised in filling with concentrates instead of highly dilute mixtures. Reductions in the need for packaging material of factors of 2-5 should be possible here in the field of cleaning agents. A further reduction is conceivable by employing returnable containers with which reduction factors of 5-10 are again possible. A few important demands, however, must be satisfied for returnable containers of this product group:
All thermoplastic plastics from which the described packing elements can be manufactured with suitable, known production methods (for example, blowing but, in particular and particularly preferred, injection molding) come into consideration as materials for the containers as well as for the container covers.
A prerequisite is that the plastics employed in the described embodiment of the packing comprise adequate shape stability, even given occasional application of impact loads or compressive forces, temperatures between approximately 0.degree. C. and 85.degree. C. (when being washed), ultraviolet rays (due to natural or artificial light). A further prerequisite is that the plastics employed are compatible with the chemicals contained as filled product (particularly detergents, cleaning agents, rinses, detergents, disinfectants, water-treatment agents), even at higher temperatures up to approximately 85.degree. C. as well as prolonged influencing times.
It is desirable that the plastics employed can either be supplied for reemployment (production of plastic granules) or to an unproblematical, thermal utilization (burning) after the expiration of the multiple-use time. For this reason, halogen-free, particularly chlorine-free plastics are to be preferably employed.
Polyethylene and polypropylene, particularly high-pressure PE or, respectively, PP are therefore especially preferred.
DE-A-28 51 605 is directed to a stackable cover or, respectively, floor for a container. The cover or, respectively, floor is constructed such that it comprises a let-in double wall and a circumferential edge in which a channel for mating acceptance of the cover or, respectively, floor edge of the container is shaped.
WO-A-92/12062 discloses stackable, returnable containers for hazardous materials. The container covers comprise no grip.